When President Obama meets at the White House on Thursday morning with Democratic and Republican leaders from Congress, all of Washington will be watching carefully for any hint of progress toward a deficit-reduction deal that can pave the way for a politically painful Congressional vote to raise the federal debt limit. But one group will be watching with a pronounced wariness: Obama’s liberal supporters (also known as his toughest critics). Stop me if you’ve heard this one before, but liberals are frustrated with Barack Obama. This will be familiar to anyone who has followed his presidency from health care reform (fight for a public option!) to terrorist detention (close Gitmo!) to Afghanistan (get out now!) to Wall Street oversight (appoint Elizabeth Warren!) In the case of the wrangling over the debt ceiling, the complaint–from activists, bloggers, and some Democrats in Congress–ranges from substance to tactics to messaging, but can be boiled down this way: You’re getting played. Here are the critique’s three basic components:

He Blew His Best Shot: Obama was directly confronted with this critique at Wednesday’s Twitter “town hall” event, in which he was shown a widely-retweeted question from New York Times columnist Nick Kristof. Picking up on a theme liberals have debated for months, Kristof asked whether “it was a mistake” that Obama failed to win a borrowing-limit increase as part of the grand deal he cut with Congressional Republicans last December. The idea is that Obama enjoyed more leverage over Republicans back then, because the GOP was obsessed with preventing a scheduled expiration of the Bush tax cuts. (They got their wish in the deal, in exchange for allowing an extension of unemployment benefits and a payroll tax break.) The question made the President sweat. Obama’s response to Kristof? “That wasn’t the deal that was available.” (Kristof was not impressed, later tweeting that there was no way to know because Obama never pressed the issue.)

He’s Ineptly Framed the Debate: Liberals have complained for a while now that Obama didn’t engage in the debate over the debt limit early enough or forcefully enough. As far back as April, Nation columnist Eric Alterman complained that it was “long past time for this president to get off the ropes and come out punching.” Others lament that Obama hasn’t used the bully pulpit more to explain the potentially horrendous consequences of a default. And some House Democrats, who have felt excluded from Obama’s talks with Republicans, have also complained that Obama is sending weak signals to the GOP and not mounting a robust fight for the left’s priorities. It’s true that liberals were heartened by Obama’s June 29 press conference, at which he cast GOP as champions of the super-rich and defenders of absurd corporate tax loopholes. (“Those who are hoping he will continue to make a strong moral argument in favor of ending [high-end tax cuts] should be pleased by what they heard,” wrote the Washington Post‘s Greg Sargent.) But many fear it was too little, too late.

He’s Caving In: Ultimately, what liberals fear most is that Obama, desperate for a deal that could improve his 2012 re-election prospects by boosting the economy and positioning him as a results-producing centrist for 2012, will agree to trillions of dollars in spending cuts–including trims to cherished entitlement programs like Social Security, Medicare and Medicaid–in exchange for relatively puny tax revenue increases. (According to multiplereports this morning, Obama plans to put Social Security cuts squarely in play at Thursday’s meeting.) Some reports suggest that the ratio of spending cuts to tax increases could be on the order of five to one. Given that Obama’s original negotiating position was that the debt ceiling be raised without conditions–a stance he soon abandoned–it’s easy to see why the left feels dismayed. That’s particularly true when you consider that the nation’s borrowing limit has been raised dozens of times by multiple presidents, none of whom made anything like the substantive policy concessions that Obama is now discussing. The New Republic‘s Jonathan Chait argues that Obama has proven himself a weak negotiator, and frets that, as a result, “the risk of Obama acceding to some dreadful policy choices is real and worrisome.” The prominent liberal blogger Digby is confounded that Obama is tying deficit reduction to the debt vote at all. And in a statement to TIME, Progressive Change Campaign Committee co-founder Adam Green says that any deal accepting entitlements cuts instead of higher taxes on the rich will amount to “a defining moment of presidential weakness.”

There are plenty of counterarguments to these complaints, of course. Obama might say that he has very little leverag eover the Republican Party whose base despises the idea of increasing the debt limit and which appears more willing than Democrats to flirt with economic disaster. He might argue that this debt limit vote is different from past ones because the nation’s fiscal health has rarely if ever seemed so dire. He might also say (though probably not in public) that he’s never minded being positioned between angry partisans on the left and the right. None of that will mollify his frustrated liberal supporters, of course. But spirited criticism from the left hasn’t moved Obama before, and there’s little reason to think this time will be any different.